Information storage libraries require that the alignment between the storage cells of the libraries that hold the data cartridges and the gripper mechanism used in the robotic systems must be held within narrow tolerances. The arrays of storage cells are generally bolted to the frame work. The accuracy achievable with just a simple bolting is severely limited. This results in misalignment between the robotic gripper and the cartridge in the cells. Further, the array of storage cells may distort from its nominal rectangular shape. Often the location of every cell in the array is in error by a considerable amount and thus the storage cell to robotic gripper accuracy is not achieved.
Some prior art systems solved the alignment problem by placing a distinctive mark on the corners of the storage cells and then using a video camera to provide feedback to the accessor and especially the robotic gripper to achieve the correct location for each storage cell. This solution is extremely costly in that the robotic gripper must carry a video camera. Then the camera has to be maintained in alignment with the robotic gripper so the relationship between the image transmitted and the actual gripper position is true. It is then required to process the image and create an error function which is then used to guide the robotic gripper. With this solution, it is a matter of replacing one alignment problem with a second and neither result in a completely accurate positioning between the robotic gripper and the cartridge stored in the storage cell. There is presently no known arrangement for conveniently mounting storage cells in an information library system that enables easy and correct alignment between the storage cells and the robotic gripper and that enables accurate alignment and easy installation of the storage cells into the library.
It is, therefore, an object of the present invention to provide an enhanced storage cell mounting for information storage libraries.
Another object of the present invention, therefore, is to provide a mounting for storage cells that is easy to assemble while providing accurate alignment between the storage cells and the robotic gripper of the assessor.
There is an ongoing need for an easy mount of an array of cartridge storage cells that can be built and maintained correctly at a low cost while providing simple calibration of the array of storage cells that is sufficient in predicting the location of every cell in the array by the robotic picker.